Ask MO Anything: Stripped Fasteners on Old Motorcycles

John Burns
by John Burns

Dear MOby,

I just purchased a great ’78 Suzuki TS250. The guy before me stripped some screws on the crankcase. Having used everything from WD-40 to an impact screwdriver and even prayer, what’s next? Machine shop? Bike shops around here won’t touch it. they’ve got money to make and won’t “waste their time.”

Thx.

Annie

This was clearly a question for Joe Gresh, whose life work consists of rescuing old two-strokes and pouring concrete. He writes:

If the screw threads are stripped you’ll have to drill the screws out and use Helicoils. If (what I think you mean) the screw heads are stripped and you can’t get a purchase with a screwdriver, there are a few options:

  • Use a nice sharp cold chisel to pound a slot into the screw head, then try a flat blade tip on the impact driver (the kind you hit with a hammer.)
  • Use a pin punch (flat round) on the outer edge of whatever remains to try and rotate the screw head in the direction it needs to go, usually counter clockwise. Hit the punch with a hammer…
    • Carefully drill the center of the screw head, increasing drill size until the head falls off, leaving the main body of the screw behind. Then remove the cover or whatever the screw was holding on and clamp vise grips on the bit of the screw that sticks out to remove it.

    Note1: These options are in no particular order. A lot of it depends on your mood at the exact moment. It’s a call best made in the field.

    Note 2: You can really screw (ha!) this up if you’re not talented with tools.

    Note 3: Always remember no matter how bleak it looks, you can toss the whole thing in the trash and get another motorcycle.

    More Gresh advice can be found at the Exhaust Notes Blog.

    Heck, we’ve even seen really smart people weld an allen wrench to the offending fastener and remove it that way, which seems to cut right to the chase, if only you have a welder handy and somebody who knows how to use it…

    Joe may be half kidding about getting another motorcycle, but now that there’s ebay and the www, there are plenty of entire TS engines and parts for sale for not a lot of money – a lot of money of course being a relative thing. Mrmonkeyclaw, for one, has 99.7% positive reviews on his ebay site.

    Stuck fasteners really are the bane of working on old vehicles; take solace in that you are not the only victim, not by a long shot. A lot of what separates us garage mechanics from professionals is their ability to quickly deal with these kinds of time-consuming hold-ups – mostly by avoiding them in the first place by refusing to work on 42-year old things.

    When you’re not being paid by the hour, though, you can generally unstick the worst of them eventually if you stick with it and attempt patience. Find a good radio station or podcast, take beer or coffee breaks as needed – and when dealing with what appear to be Phillips screws on Japanese bikes in the future, remember to keep holy the JIS (Japanese Industry Standard) screwdriver. They may look the same, but you can apply a lot more force with a JIS driver than a Phillips one. Many historians now believe that not making the presence of JIS fasteners in its products more widely known was a main form of Japan’s revenge for WW2 unpleasantness.

    This Vessel Megadora 980 Impacta P2x100 #2 Cross Point Impact JIS Screwdriver was designed to avoid just the problem you’re experiencing, and JIS bits for your impact driver are also widely available.

    Good luck!

    Related reading: 10 Steps to Removing Stuck Fasteners

    Send your moto-related questions to AskMOAnything@motorcycle.com. If we can’t answer them, at least the price is right, and we’ll do no harm in the time it takes to seek out a believable answer.

    John Burns
    John Burns

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    5 of 21 comments
    • TC TC on Apr 04, 2020

      I have better luck with a cordless impact driver, those hammer powered ones seemed to want to jump out of the screw slot. Also, after you get the stripped phillps screw out, buy a set of allen head screws for the engine.

      • Jon Jones Jon Jones on Apr 06, 2020

        Those replacement allen sets were a big seller back in the '70s and '80s. Then Honda(?) started the wonderful trend of 6mm case bolts with 8mm hex heads.

    • Meaty Midrange Meaty Midrange on Apr 05, 2020

      Warming the metal around the stuck fastener with a propane torch has worked for me.

      • See 1 previous
      • Jon Jones Jon Jones on Apr 06, 2020

        OMG, John Burns hisself just upvoted me!!

        I'm finally complete!

        BTW, I once owned a nice '74 TS250...

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